list devices.
Only devices which provide a EDID data block and the EDIDs header is valid will be counted.

-v show each device by its node name.

-d=POSITIONAL_NUMBER , -d POSITIONAL_NUMBER

position in device list.
The numbering of monitors starts with zero for the first device. To get the
number of all available devices use "xcmddc -l". The EDID data block is dumped to stdout.

--force-output switch EDID header verificatcationn off.

--identify dump the error code as integer to stdout.

--i2c=NODE_NAME , --i2cNODE_NAME

select the i2c device node file. The EDID data block is dumped to stdout. The --i2c option is much faster than the -d option. This is because of much fewer timeouts reuired for counting the valid i2c device with the -d option.